Process for treatment of metals



Patented on. 243-, rear.

1., the

lent

FRED PALMER AND FRANK PALMER, OF SPOKANE, WASHINGTUN.

PROCESS FORTREATMENT OF METALS.

No Drawing.

To aZlwhom it mar-y concern:

Be it known that we, FRED PALMER and FRANK PALMER, citizens of theUnited States. residing: at Spokane, in the county of Spokane and Stateof Washington, have invented certain new and useful Improvements 1nProcesses for Treatment of Metals, of

which the following is a specification.

This lnvention relates to an improved process for refimngmetal.

The primary object of the invention is the provision of a special liquidbath or solution, for quenchmg of heating metals,

as a means of refinement of said metals.

A further object of the invention is the provision ofa liquid hath madefromthe subsequently described formula, and adapted for carburizingmetals when. quenchedtherein.

A further object of the invention is the provision of a liquid solutionof the above described character specifically adapted to simultaneouslyharden, toughen, and carburize mild steels, by their immersion therein,when heated to a critical temperature. Other objects and advantageswillbe apparent during the course of the following detailed description. M y

The specific proportions of ingredients in the improved metal refiningbath are as follows:

Sodium sulphate (Na SO 2 ounces soeitm' chloride NaGl 8 ounces Potassiumferrocyanide (H lde WVater (H O) 1 gallon The bath or solution ispreferably used in connection with mild steels of varying carboncontent, and which may have as high a carbon content as 1.1% or 1.2%. Ahigh degree of refinement and carburization of; this grade of metal hasresulted from the precise use of the above proportioned formula,although the same maybe varied slightly to suit the analyses of thevarious ingredients; as where an alkali water is used, the sodiumsulphate can be decreased proportionately.

.ing from 1380 to 1460 Fahrenheit.

Application filed A ril 29,1921. Serial No. ies r94.

The mild steel or other metal is first slowly heated throughout until itreaches its critical temperature, which takes place at a color glow ofbright cherry red, rang- At this temperature the grain of the steel isrefined until it possesses the finest structure which it is capable ofassuming. After the metal is heated evenly throughout, it is taken fromthe furnace at its critical temperature, and suddenly quenched in a coldbath of the above set forth ingredients and proportions. The bathpreferably ranges from 40 to Fahrenheit; and is of sufficient quantityto evenly cool the metal throughout, without itself absorbing too muchheat from the metal.

By reason of its sudden immersion in this bath, the refined grain of themild steel is retained, the immersion, hardening, toughening andcarburizing the same. The toughening, hardening, and carburieing areeffected simultaneously by chemical action of the solution upon theheated steel, and

an analysis of the physical properties before and after treatment, theultimate tensile strength was shown by a Reihle machine to have.increased from 64,000 pounds per square inch to 91,200 pounds per squareinch; while the percentageof carbon as demostrated by Prof. Arnoldschromic acid test was increased from 1.1% to 2.058%. Thus the specialbath treatment of mild steel will produce a straight carbon tool steelof exceptional physical properties.

" Water (H O) Various alterations in the process may be made withoutdeparting from the spirit of the invention, or the scope of the claims.

I claim:

1. A liquid bath for treatment of metals comprising sodium sulphate,salt, potassium ferrocyanide, and water. i

2. A liquid bath for treatment of metals comprising in proportion:

Sodium sulphate a SO,) 2 ounces Sodium chloride (NaGl) 8 ouncesPotassium ferrocyanide (l,Fe(CN) +3H O) 2 ounces VVater(h 1 gallon 3.The method ofhardeningand tempering metals which consists-in thequenching of a metal in a liquid-bathcomposed'ofsodium sulphate salt,potassium ferrocyanide and water.

4. The method of hardening and tempering metals which consists inheating a metal,

to the critical temperature and quenching the same in a liquid bath of,sodium sulphate, salt, potassium torrocyanide and water.

5. The method of hardening and tempering metals which consists inheating a metal to its critical temperature, and then quenchingina'liquid bathcomprislng in proportion: I

Sodium sulphate (Na SOQ "2 ounces Sodium chloride (NaCl) 8 ouncesPotassium ferrocyanide (K ,Fe(GN) +BH O) 2 ounces 1 gallon 6, The methodof carburizing metal which consists of heating said metal to a criticaltemperature: and:quenching said metal in bath of sodium sulphate, salt,potassium ferrocyanide and ,water.

7'. The method of carburizing metal, which consists of heating saidmetalto its critical temperature and quenching in a liquid bath comprisingin; proportion Sodium sulphate (Na SO "2 ounces Sodium chloride (NaCl) 8ounces Potassium, ferrocyanide (K Fe(CN) -|-3H,O) 2 ounces l/Vater (H O)1 gallon 8. The method'of producing a straight carbon steel, whichconsists in-heating a mild 1 ,assnoa steel to its critical temperature,and quenching the same in a bath of sodium sulphate, salt, potassiumi'errocyanide, and water.

9. The method of producing a straight carbon steel, which consists inheating a mild steel to its critical temperature and quenching the samein a liquid bath comprlsing in proportion Sodium sulphate (Nafith) 2ounces Sodium chloride (NaCl) 8 ounces Potassium ferrocyanide (K Fe(CN)+3H O) 2 ounces ater (H O) 1 gallon 10. The method of refining mildsteels which consists in simultaneously hardening, toughening andcarburizing said mild steel to produce a tool steel by heating said mildsteel to its critical temperature and Sodium sulphate (Na SOQ "2 ouncesSodium chloride (NaCl) 8 ounces Potassium ferrocyanide (K,Fe(CN) {-3H O)2 ounces \Vater (H O) 1 gallon 12. The method of refining metals whichconsists in heating a metal to a bright cherry red color, and suddenlyimmersing the same in a cold bath of sodium sulphate, salt, potassiumferrocyanide and water.

13. The method of refining metals, which consists in heating a metal toa bright cherry red color, and suddenly immersing the same in a coldliquid bath, comprising in proportion:-

Sodium sulphate (Na,SO,) "*2 ounces Sodium chloride (NaCl) S ouncesPotassium ferrocyanide (K,,Fe(CN) -|-3H O) "2 ounces Water (H O) a 1gallon FRED PALMER. FRANK PALMER.

